Fifty percent of Saimaa ringed seal pups born between the years of 2014-2017 entered the world in a snowdrift constructed by volunteers.

The population of the endangered Saimaa ringed seal has risen to 392 individuals in Finland, according to the Ministry of Agriculture and Forestry. An estimated 86 seal pups were born this year, a figure that experts say bodes well for the species.

In 2017 a total of 286 snow dens were built by volunteers, and 74 seal pups were eventually born in some of them. The figure for the whole of 2014-2017 is 190 pups born in close to 800 artificial snow banks. Just over half of all Saimaa ringed real pups born in this period entered the world in a den constructed by humans.

There are 13 breeding areas in the country, located mainly in the national parks of Kolovesi and Linnansaari in south-east Finland. The most seals were found in the breeding grounds of Pihlajavesi, where 124 were counted.

The Ministry of Agriculture credits volunteer helpers for the positive growth. Since 2014 people have gathered together to shovel snow into larger snowdrifts on rocks and shorelines, so the seals can burrow birthing dens into them.

Climate change has depleting the seals' natural winter habitats as the warmer winters have limited snow and ice cover. For decades, dozens of seals also died each year in area fishing nets.

After a strong public information campaign, the Ministry of Agriculture reports that the number of Saimaa seals killed by fishing is now in decline. It estimates the current size of the species' territory at some 2,700 square kilometres.

A endemic subspecies on the rebound

The Saimaa ringed seal is unique to Finland's Saimaa lake system, where the species was isolated by the last ice age some 9,500 years ago.

The population fell to between 100 and 150 seals in 1983. The fact that the 2018 count has estimated a population close to 400 is significant, as this has long been seen as a benchmark for avoiding the threat of the endemic species' extinction.

The number of seals in the 2018 count was determined through breeding analysis and observations of individuals resting on lake ice.

This year's tally found 109 birthing Saimaa ringed seal females, as opposed to 83 in 2012, and only 77 in 2007.